What is calculated by subtracting fuel used for start, engine run up, and taxi from Ramp Weight?

The concept being addressed in the question involves understanding the various weights of an aircraft throughout its operation. By subtracting the fuel used for activities such as engine start, engine run-up, and taxi from the Ramp Weight, you determine the Takeoff Weight.

Ramp Weight, also known as Ramp Gross Weight, is the total weight of the aircraft when it is parked at the ramp or gate, fully loaded with fuel, passengers, cargo, and other necessary items. Prior to taking off, the aircraft consumes a portion of this fuel during preliminary operations. This fuel is used for starting the engines, maintaining engine operation during the run-up, and the fuel consumed while taxiing to the runway.

By subtracting this fuel consumption from the Ramp Weight, you are left with the weight of the aircraft ready for takeoff, which is designated as the Takeoff Weight. This weight is critical for ensuring that the aircraft complies with performance metrics for a safe departure, considering factors such as maximum takeoff weight limitations, runway length, and environmental conditions.

Understanding this calculation is essential as it directly impacts flight safety and performance. Other weight categories like Landing Weight or Zero Fuel Weight represent different considerations in flight planning and fuel management. However, for this specific calculation involving the fuel used